suppress image cleanup because it produces an error, see https://travis-ci.org/JurajKubelka/PharoSprint/jobs/220720518#L773
suppress image cleanup because it produces an error, see https://travis-ci.org/JurajKubelka/PharoSprint/jobs/220720518#L773

JurajKubelka/PharoSprint,JurajKubelka/PharoSprint